Garold664

.main
      .child
      .child
      .child
      .child
      .child

.main {
  background-color: #e1e1e1;
  width: 100%;
  display: flex;
  flex-direction: row;
  flex-wrap: wrap;
  justify-content: center;
}

.child {
  margin: 5px;
  background-color: green;
  height: 20px;
  width: 30%;
}